Kozar's in the South Amercica

My name is Joao Kozara Filho. My granfather was Nicolae Kozar that was married with Maria Retzer in Brazil. The father of my grandfather was John Kozar. John came to South America in the early of 1920 from Romenia (Europe). My father's name was changed when was put a letter "a" in the end of my surname. The daugther's John Kozar were Rose and Anna Kozar. Roseimmigrated to US (New York) and Anna came to Brazil. The other son of John Kozar was João Kozar that immigrate to Brazil with my grandfather Nicolae. I would like to know information about my parents in US. Thanks, João Kozara Filho